Artificial teeth



Jan. 15, 1935. H, SCHRDER ETAL 1,987,712

ARTIFICIAL TEETH Filed Aug. 8, 1931 d C m a @i i g (Fj: 5.9.4 i F' .2 @W

Elgr m5 SY/mh@ Pafenaa Jan. 1s, 193s UNITED VSTATES PATENT OFFICE ARTIFICIAL TEE'IHl Application Auguste, 1931, serial No. 555,912 In Germany November 6, 1930 1 Claim. (Cl. 32-8) It has already been suggested to form artificial teeth in such a manner, that the masticating surface of the one tooth angular at the edge is holvangle of the edges of which meet under an angle of and that in such a manner, that the tectiform or roof-shaped masticat'ing surfaces of the superior maxilla, being provided with a bevel of a certain angle in the direction of the cheek, match the cavity. The cavity, being formed by a certain trihedral angle arrangement, is situated in every single tooth. This configuration does not, however, render a free and unhindered maxillary movement possible during the masticating process, because the molars of the inferior maxilla have been provided with ascending bevels in the direction of the cheeks and in consequence thereof the teeth of the superior maxilla are forced to glide up with the tectiform or roof-shaped part of the masticating surfaces of the upper molars along said bevels during the lateral and mixed lateral and forward motion of the teeth. In view of the fact, that thereby certain points of the teeth of the inferior and superior maxilla establish contact with each other, which originally have not been intended to do so, there will be a possibility of easily lifting olf the prothese carrying the artificial teeth. The same applies to another kind of arrangement which has become known, in whichthe masticating surfaces of the teeth are provided with small protuberances or projections.

One of the objects of the present invention is to provide artificial teeth which will facilitate as much as possible the mixed lateral and forward motions controlled by the motion of the maxillary joint during the masticating process.

'I'here will also be a possibility to impart to the teeth an appearance fully corresponding to the cosmetic assumptions when producing a prothese. By the arrangement of the upper faces of the teeth it has been rendered possible, when constructing a prothese, to displace the longitudinal axis or a part of the longitudinal axis of the one or the other row of teeth in the direction of the cheeks as well as towards the tongue, so that the teeth may be accommodated to various kinds of mastication.

The above-mentioned object ofthe present invention may be realized by providing a curved 5 transverse ledge on the dome-shaped teeth and/ or the counter teeth, which form the prothese.

The dome-shaped molar teeth and/or the counter teeth may be provided with a substantially S-shaped transverse ledge allowing lateral and 1.0 longitudinal movements as well as every kind of combined lateral and longitudinal movements of the teeth.

The S-shaped conguration of the transverse ledge is particularly advantageous forvthat reason that, on the one hand, it improves the chewing process and, on the other hand, it allows the transverse ledge to glide outwards without being interfered with, owing to the fact that the mould or recess, being formedby two adjoining teeth, shows no projection or protuberance which has to be passed, as a result of the situation of the S-shaped transverse ledge at the mesial sides of the molars towards the cheeks and at the distalsides of the molars towards the tongue, so that a practically unimpeded lateral motion and a mixed lateral and forward motion to the fullest possible extent of all maxillary motions that may be possible, is ensured.

The masticating surfaces of the frontal premclars show in accordance with the present invention in the forward section a short, horizontal surface, or a surface whichis slightly inclined upwards or downwards, whilst they are forming the mould or recess in the rearward section. The tooth has, therefore, been given a dissymmetric shape and that for the `reason of its functional purposes.

The highest part of the cupola or dome-shaped teeth and of the mould or recess teeth may be placed in the centre of the teeth or in front or behind the centre of the teeth for the purpose of attaining articulatory correct proportions in accordance with the prevailing requirements.

The upper surfaces of the teeth may be smooth or they may show channelled indentations.

In the accompanying drawing the invention has been illustrated by way of example,

Fig. 1 being a side view of the premolars and molars of the right half of a set of teeth, whilst Fig. 2 is a plan viewof the teeth of the inferior maxilla in accordance with Fig. 1.

Fig. 3 is a sectional View on the line A-B of Fig. 2, and

Figs. 4 and 6 are further examples of performance of the teeth forming the moulds or recesses, and

Fig. 5 represents a sectional View online C-D in accordance with Fig. 4.

Fig. rI shows teeth having transverse ledges of a diil'erent shape.

In the example of performance in accordance with Figs. 1-3 the teeth o1' the superior maxilla, a; b, c, d are dome-shaped and are engaging in the recesses or moulds between each two of the teeth of the inferior maxilla. Each two of the teeth of the inferior maxilla are forming a mould or a recess in which the dome-shaped tooth appertaining thereto, engages. These moulds or recesses may be of the most heterogeneous designs. In the example of performance in accordance with Figs. 1 to 3, the moulds or recesses are made to be concave in longitudinal, as well as in cross section. They may, however, as shown by the example of performance in accordance with Figs. 4 and 5, also be concave in longitudinal section and plane in cross section, in which case the surface of the mould or recess forms a cylindrical surface. As shown in Fig. 6, the surface may also be plane in longitudinal section and, in accordance with Fig. 3, trough-shaped; in this case, too, the surface of the mould is cylindrical. The above is true of a side of one tooth. Furthermore, however, the moulds may be plane not only in longitudinal section, but also in cross section and this would represent a longitudinal section in accordance with Fig. 6 and a cross section in accordance with Fig. 5.

The lower frontal premolar e is of such dissymmetrical design, that it shows in its front section a face i being straight or slightly inclined forward and downward and occupying about 1/5 to l/2 o! the total surface, from the rearward edge of which a straight or concave surface k is extending obliquely rearwardly and downwardly under a rather accentuated angle.

As seen from Fig. 1, and particularly from the tooth c, the dome-shaped teeth may be provided with a transverse ledge m being situated either in front or behind the centre of the tooth.

Fig. 7 shows an S-shaped ledge having its two ends bent in opposite directions, which can be used on dome shaped teeth and/or on counter teeth. A

We claim:

In a set of artificial teeth. in combination, a pair of counter teeth forming a recess. a domeshaped molar tooth of one maxilla adapted to engage in said recess, S-shaped transverse ledge on at least one of said teeth, said ledge allowing lateral andlongitudinal movements as well as every kind of combined lateral and longitudinal movements of the teeth.

HERMANN SCHRDER. ROBERT NUssBAUM and a substantially 

